Residential Solar Fires – What Caused Them?
We previously discussed the fires caused by solar panels when problems at some Walmart stores were widely reported in the media. Now a series of residential fires, also caused by solar panels, are making the rounds in the news. This makes for a good time to go over the types of issues that lead to these fires and how you can be secure in your decision to install a solar power system without the constant fear of a house fire.
What Caused These Fires?
As solar adoption continues to grow, it stands to reason that problems with the technology will also grow. In the news lately, we’ve seen reports of lawsuits filed because of faulty solar installation. These fires were caused by solar panels that were damaged during installation, bad connections, or improper grounding. It is important to note that in all of the cases, the fires were caused not by the systems themselves, but by poor installation. Let’s go over each of the problems that might have caused a fire and explain how they happened.
When a solar panel suffers damage, it may have increased electrical resistance in the area of the damage. This causes that area to become hotter than it normally would. Depending on the severity of the damage, this heat could become intense enough to ignite flammable materials nearby. This, of course, includes your roof.
Panels may be damaged at the factory and not thoroughly inspected by the installer before placing them on your roof. They may become damaged by the installer during the process of placing them on your roof should they be careless. An undamaged and carefully installed solar panel will not have the types of hot spots that lead to this problem.
In some of the installations, bad connectors were to blame. A bad connection causes a similar problem to the hot spot. When the connection isn’t optimal, electricity must work harder to flow past the connection (termed electrical resistance). This causes a rise in temperature, which can result in a fire at the location of the connector.
Bad connections can be caused by the use of low-grade solar panels that ship with poor connectors or by shoddy workmanship on the part of the installers. Just like the electrical connections in your home, problems can also occur if aging insulation begins to crack or is damaged by rodents or other external factors. Both of these problems are caused by either improper installation or poor maintenance.
Electricity follows the path of least resistance. In the case of a power surge, such as that caused by lightning or a major malfunction, you want the electricity to travel someplace that it will not cause damage. A properly grounded system will divert this sudden surge of electricity safely into the ground. If the system is not grounded properly, the electricity could arc and cause a fire.
A solar power installation performed by qualified professionals will always be properly grounded according to the electric code.
Lack of NEC 2017 Rapid Shutdown Compliance
Electricity and water do not mix. Neither does electricity and human flesh. Both of these things are a huge concern for firefighters responding to a fire with active electrical panels on the roof. Before firefighters can safely go about their job, they must make sure that power to the solar panels is completely shut down.
As solar installations grew in size and voltage, the National Electrical Code responded with requirements that solar panels are installed with a rapid shutdown system. This means that a firefighter can quickly shut down the power and safely begin the process of putting out a fire much more quickly. Solar installations without this feature may allow the fire to burn longer, doing more damage in the process.
These automatic systems will also shut down the system if a fault is detected, potentially preventing a fire in the first place. State of the art rapid shutdown functionality mitigates many of the issues above, as the entire array becomes inert if an arc fault or ground fault is detected, long before a fire can start.
How Do I Find a Qualified Installer?
We’ve talked a lot about how these causes of fire could have been prevented if they were done by a fully licensed and qualified installer. But thus far, we have not told you how to find a qualified installer. The first step you should take is to find out if your state has any certification requirements for solar installers. If it does, then you should immediately disqualify any candidate who does not have that certification. Of course, there are more steps you can take to make sure that you are getting the best installation possible.
We all know the problem of needing experience to get a job, but needing a job to get experience. Because of this, you may be tempted to give an upstart installer a chance. Remember though, that an inexperienced installer could cause severe problems down the line. These problems could include a house fire. This does not mean that you cannot hire a new-to-market company. Just be sure that the lead installer is someone who has plenty of experience prior to starting the company, preferably with a NABCEP certification, and that the company has an employed master electrician to over-see the wiring.
Industry growth is fast and furious. SolarEdge expects 67% to 74% growth year over year. There is an ever increasing labor shortage to install all of this advanced technology. The importance of choosing a contractor that’s been around for many years is imperative for quality training purposes.
Many of the system fires that have happened were performed by installers that hire temporary labor. This is also a huge red flag. Temporary labor likely does not have the training required to perform the job up to the high standards required for safety. Make sure that the company you hire has permanent employees and that their training program insures that the employees are fully qualified before they work on your house.
Finally, make sure that the installer is proposing an NEC 2017 rapid shutdown compliant system, such as that of SolarEdge. This will further reduce the risk of fire and ensure that if the worst does happen, firefighters will be able to respond more quickly and minimize the damage.
Are Solar Panels Safe?
Yes! While there have been fires caused by solar panels, those were cases of shoddy installation and lack of modern safety mechanisms. There is nothing inherent in the design of a solar energy system that makes them susceptible to fire. As long as you hire a licensed, reputable installer with experience and ensure that the proper safeguards are in place, your new solar panels will give you decades of worry-free electricity and an excellent ROI in this area of 10-12 years.
To find out how Mountain View Solar keeps our solar installations from becoming a hazard to you and your family, contact us today to schedule your FREE, zero-pressure consultation. In the 10+ year history of our company, we’ve never had a system catch fire.